The field of the disclosure relates generally to gas turbine engines, and more specifically, to methods and apparatus for reducing nozzle stress in a gas turbine engine.
A gas turbine engine generally includes in serial flow communication a compressor, a combustor, and a turbine. The compressor provides compressed airflow to the combustor wherein the airflow is mixed with fuel and ignited, which creates combustion gases. The combustion gases flow to the turbine which extracts energy therefrom.
The turbine includes one or more stages, with each stage having an annular turbine nozzle set for channeling the combustion gases to a plurality of rotor blades. The turbine nozzle set includes a plurality of circumferentially spaced nozzles fixedly joined at their roots and tips to a radially inner sidewall and a radially outer sidewall, respectively. Each individual nozzle has an airfoil cross-section and includes a leading edge, a trailing edge, and pressure and suction sides extending therebetween. Typically, a useful life of a nozzle is limited to the life of the nozzle trailing edge. This is at least partially caused by a large strain range that the trailing edge passes through during engine start-up and shut-down. For example, exposure to changing temperatures, in combination with the varying thickness of each nozzle, causes strain on the nozzle that may reduce a useful life of the nozzle.